Conventionally, an image-surface phase difference AF is known as an AF function system employed in an electronic apparatus represented by a digital camera having a photographing function (e.g., see Patent Literature 1). In a solid-state image pickup device that realizes the image-surface phase difference AF, normal pixels for obtaining pixel signals (color signals) that constitutes an image as well as phase-difference detection pixels for pupil splitting of incident light are arranged at predetermined positions.
In a conventional phase-difference detection pixel, a metal light-shielding film is formed between an on-chip lens and a photoelectric conversion layer. The metal light-shielding film has an opening shifted with respect to an optical axis (optical center) of the on-chip lens. In addition, a light-shielding structure is provided between a pair of phase-difference detection pixels arranged adjacent to each other. The light-shielding structure is for reducing optical color mixing.
A phase-difference signal is calculated on the basis of outputs of the pair of phase-difference detection pixels having openings at different positions (e.g., phase-difference detection pixel opened on left-hand side thereof and phase-difference detection pixel opened on right-hand side thereof). The calculated phase-difference signal is used for controlling focus.